Try this mod,
https://vborg.vbsupport.ru/showthread.php?t=286441
What does the bounced email handler do?
It stops sending emails to addresses that are no longer valid. This helps keep your email from being marked as spam.
More technically:
- It collects bounced emails, counts them and marks user accounts as "do not send email".
- It stops sending "new post" notifications to those addresses.